RESUMO
A fatty acid binding protein has been isolated from chicken gizzard smooth muscle. The partial amino acid sequence (EMBL P80565) of this protein shows high sequence similarities with other members of the fatty acid binding protein family. This is the first fatty acid binding protein isolated from smooth muscle. It may be involved in the regulation of smooth muscle contraction by transporting polyunsaturated fatty acids (e.g. arachidonic acid).
Assuntos
Proteínas de Transporte/metabolismo , Músculo Liso/metabolismo , Proteína P2 de Mielina/metabolismo , Proteínas de Neoplasias , Proteínas Supressoras de Tumor , Sequência de Aminoácidos , Animais , Proteínas de Transporte/química , Galinhas , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Proteína 7 de Ligação a Ácidos Graxos , Proteínas de Ligação a Ácido Graxo , Humanos , Dados de Sequência Molecular , Contração Muscular , Músculo Liso/fisiologia , Proteína P2 de Mielina/química , Homologia de Sequência de AminoácidosRESUMO
In the present work we show with different binding assays chicken gizzard myoglobin is able to bind fatty acids and bromosulphophthalein (BSP) in vitro. The fatty acid binding depends on the oxygenation of the myoglobin. Freshly prepared chicken gizzard, chicken or bovine heart myoglobin have a high fatty acid binding capability. However, when oxy-myoglobin in converted to met-myoglobin by dialysis against acidic buffer at high ionic strength (or when commercially available myoglobins are used) a 60-70% lower fatty acid binding capacity is found. Like bovine serum albumin (BSA), gizzard myoglobin has the highest affinity for unsaturated fatty acids and a lower affinity for saturated fatty acids or dyes. Chicken gizzard smooth muscle myoglobin may function as an additional fatty acid binding protein in vivo.